US intelligence knew of an imminent attack weeks ago.
https://ru.usembassy.gov/security-al...next-48-hours/
Location: Moscow, Russia
The Embassy is monitoring reports that extremists have imminent plans to target large gatherings in Moscow, to
include concerts, and U.S. citizens should be advised to avoid large gatherings over the next 48 hours.
Actions to Take:
Avoid crowds.
Monitor local media for updates.
Be aware of your surroundings.